Thread-tensioning device



April 7, 1931. A; HQFFMANN 1,799,165

THREAD TENS IONING DEVICE Filed Jan. 6, 1930 Patented Apr. 7, 1931 AUGUST HOIEMANN, 01 LEIPZIG, GERMANY THREAD-TENSIONING DEVICE Application filed January 6, 1930, Serial No. 418,745, and in Germany May 14, 1928.

This invention relates to a thread tensionin device for use on bobbin winding mach1nes and the like, in which the thread is guided between two tension discs adapted to n rotate in a direction opposite to the travel of the thread. The main object of the invention is the provision of means to control the rotation of the tensioning devicein dependence of the supply reel and, especially in connection with threads of low tensile strength, to prevent excessive'strain and consequent rupture of the thread. In order to attain these objects, the invention consists in the provision of means to enable an even and '15 jerkless rotation of the reel from which the thread is unwound.

Thread winding machines in which thethread brake acting on the reel is applied stronger whenever more thread is supplied as 2 the bobbin is just able to consume, have the disadvantage of comparatively complicated construction without, however, ensuring the prevention of thread rupture in the case of delicate threads. With these devices it is practically impossible to so carefully adjust the brake levers as to avoid the occurrence of shocks. The brake, as a rule, will stop the reel entirely, so that the quickly moving thread is forced to suddenly cause its rotation from the position of rest.

According to the invention these disadvantages are eliminated and an even windingup of the thread is obtained by causing same to pass between two tension wheels which are positively driven from the reel in a direction opposite to the travel of the thread, so that a quicker rotation of the reel will, in consequence, cause a quicker rotation of the brake. The gradually increasing tension of the thread between the bobbin and the thread tension device causes a retarding action in the rotation of the reel, so that the thread will never hang down to such a degree as to require some longer time for its being taken up, but will always exert an even pull on the reel which, in consequence, will-rotate evenly and not j erkingly as is the case hitherto.

The invention also avoids the disadvantage ertaining in two-disc tension devices in it which the said discs are rotated by an evenly rotating shaft and are, therefore, not in dependence of the rotations of the supply reel.

The accompanying drawing diagrammatically illustrates the-invention by way of example. 1

Fig. 1 is a side elevation of.the arrangement and Fig. 2 a plan View thereof.

In this drawing a is the shaft of the supply reel upon which a chain wheel or a pulley b is arranged and from which a chain or a belt is passed to another chain wheel or pulley b on the brake shaft g. Theltwo tension discs h are slidably keyed to this brake shaft and are lightly pressed against one anotherby means of adjustable springs or a weight. This way of applying pressure to the tension discs is well known and, therefore, not shown in the drawing. The pressure on the tension disks must be sufficient-for them to effectively accomplish their purpose, but not so great as to cause rupture of the thread.

On its way to the bobbin the thread in coming from the reel :1 is passed between the two tension discs It so that it moves in the direction opposite to the direction of the said discs. Prior to its passing between the tension discs the thread is guided through the usual cleaning or stripping device 71 which, in this case, is arranged upon a lever m oscillating on a pin n so as to adapt itself to the slackness of the thread and prevent its becoming entangled.

Owingto the fact that the thread tension device is positively moved by and together with the reel so as to be in dependence thereof, undue advance of the reel is prevented and a practically even rotation of the latter is ensured. As a consequence the thread,

during the winding operation, willnever be subjected to any excessive strain and it is evident, therefore, that even ver delicate threads may be wound without risk of rupture. g

The tension discs 7:. may consist of or be covered with some smoothing material such as paraflin, wax, or the like, so that in addition to tensioning they will also serve to make the thread smooth and flexible.

What I claim is 1. In combination with a thread supply reel rotated by the withdrawal of thread therefrom, a plurality of rotative tension disks, means for transmittin rotary motion from the supply reel to sai tension disks, and means for conducting thread withdrawn from the supply reel between said tension disks in an opposite direction to their direction of rotation.

. 2. In combination with a thread supply reel rotated by the withdrawal of thread therefrom, a pair of rotative disks, means for impelling said disks lightly together, means for transmitting rotary motion from the supply reel to said disks, and means for conducting thread withdrawn from the supply reel between said disks in an opposite direction to their direction of rotation.

3. In combination with a thread supply-- reel rotated by the withdrawal of thread therefrom, a pair of rotative disks, means for impelling said disks lightly together, a direct mechanical driving connection arranged between the supply reel and said disks whereby rotation of the latter is dependent on rotation of the former, and means for conducting thread withdrawn from the supply reel between said disks in an opposite direction to their direction of rotation.

In witness whereof I afiix my signature.

AUGUST HOFFMANN. 

